Propeller regulator assembly



Oct`. 7, 1952 w. 1. BLANCHARD ETAL 2,612,959

PROPELLER REGULATOR ASSEMBLY Original Filed July 9, 1942 5 Sheets-Sheet1 ATTORNEYS Oct. 7, 1952 A w.'J.` BLANCHARD fr-AL. 2,612,959

' PROPELLER REGULATOR ASSEMBIY. 4

original Filed July 9, 1942 A 5 sheets-Sheet 2 l VE TOR WERNER BLljNcmRDCHARLES 5.a: Mac/Yau.

.Tou/E flames THoM/v B. MARTIN Mo, Mon/1 r z/ ATTQRN EYS Oct. 7, 1952.w. J, BLANCHARD ETAL 2,512,959

A PROPELLER REGULATOR ASSEMBLY l Original Filed July 9,l 1942 5Sheets-Sheet 5 JOHN E' n/Nes Tuo/m5 .MAR-r N w. J. BLANCHARD ETAL2,612,959 PROPELLER REGULATOR ASSEMBLY Oct. 7,- 19.52

original Filed July 9, 1942 5 sheets-sheet 4 /40 f 1% zo@ ya zu' 424 3f?Oct. 7, 1952 2,612,959

W. J. vBLANCHARD ET AL PROPELLER REGULATOR ASSEMBLY Original Filed July9, 1942 5 Sheets-Sheet 5 INVENTOR WER/15918 1r/mec Clanes 5.1 ne NEALJOHN EHAINES THoMAs B. MART/N ATTORNEYS Patented Oct. 7, 1.95/2

PROPELLER REGULATOR ASSEMBLY Werner J. Blanchard, John F. Haines, andThomas B. Martin, Dayton, Ohio, and Charles S. J. MacNeil, deceased,late of Dayton, Ohio, by Elise M. MacNeil, administratrix, Dayton,

Ohio;

said Werner J. Blanchard, John F.

Haines, Thomas B. Martin, and Charles S. J. MacNeil, assignors toGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareOriginal application July 9, 1942, Serial No.

450,246, now Patent No. 2,405,285, dated August 6, 1946. Divided andthis application September 11, 1945, Serial No. 615,522

7 Claims. 1

This invention relates to controllable pitch propellers for aircraft andis a division of S./N. 450,246, filed July 9, 1942 patented August 6,1946 as No. 2,405,285. i

It is a principal obj ect of the invention to provide a controllablepitch propeller with a selfcontained regulator mechanism for controllingthe operation of the propeller in response to predetermined speedrequirements.

It is a further object of the invention to provide a unitary assembly ofcontrollable pitch propeller and regulator therefore that is susceptibleof mounting and dismounting as a single unit of structure with respectto a driving shaft.

It is also an object to provide a self-contained regulator mechanism fora controllable pitch propeller in which a reservoir provides a containerfor a quantity of fluid pressure operating medium, and an enclosure forthe control apparatus including a constant delivery pressure developingmeans with iluid circuit connections from the reservoir through thecontrol mechanism and back to the reservoir, there being pressure reliefand breather means for controlling the development of pressure upon thefluid pressure operating medium exposed to the reservoir.

Another object of the invention is to provide a regulator mechanismadapted for unitary assembly upon a rotating propeller hub, to rotateabout a ii'xed sleeve from which manual control means are constantlyoperative to effect control of the regulator mechanism while thepropeller is operating.

It is also a further object of the invention to provide a regulatorassembly having its own fluid J pressure system, including a reservoirrotatable with the propeller about a fixed part having seals againstleakage of fluid medium contained within the reservoir, and means forminimizing loss f medium by reason of pressure differentials.

A further object of the invention is to provide fluid seal means for ahousing member rotating about a fixed part, with centrifugally operatedmeans for controlling a iluid by-pass around the uid seal means. l

Yet another object is to provide a controllable pitch propeller with aself contained regulator mechanism mounted thereon, and adapted formounting as a unit upon a hollow shaft, with fairing or spinner` meansenclosing the propeller hub and regulator yet leaving the Vaxis of theshaftopen for the operation of armament.

An additional object is to adapt the rotating regulator mechanism as asupport for a spinner A,fairing the propeller hub and blade roots.

(Cl. Uil-460.21)

Another object is to provide extension means for manipulation of a shaftand hub securing nut from an extended position of the hub, and lock thetightened nut in selected position.

A further object of the invention is to provide a piloted support for aspinner upon a hollow propeller shaft with means for securing thespinner firmly in position.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Fig. 1 is a longitudinal sectional View of the complete unit mounted onan engine shaft of an aircraft.

Fig. 2 is a composite view on end of the unit, with portions broken away.to show portions in section, and substantially as indicated by the lineand arrows 2--2 of Fig. 1,' portion a--o-b of` Fig. 2 being in endelevation, portion a-o-c being in section through the spinner and partof the blade socket as indicated by the line 2 0 in the upper part ofFig. l, and portion o o-b being in section through the spinner and rearhub sleeve extension to show the regulator housing and spinner supportin elevation, substantially as indicated by the line o-2 inthe lowerpart of Fig. l.

Fig.` 3 is a transverse sectional view through the regulator housingsubstantially as indicated by the line and arrows 3--3 of Fig. 1.

Fig. 4 is a sectional View through one of the blade sockets and theregulator plate showing the details of transfer passages substantiallyas indicated by the line and arrows 4--4 of Fig. 3.

Fig. 5 is a sectional view of the blade shifting mechanism, with thefiuid transfer passages shown in exaggerated relation for the purpose ofillustrating more clearly the functional relation of the elements, theview being, such as is generally indicated by the branched line andarrows 5--5 of Fig. 4.

Fig. 6 is an elevational view from the rear of the regulator plate andthe control devices mounted thereon, with parts of the housing in`section substantially as indicated by the line and arrows 6-6 of Fig.1.

Fig. 7 is a longitudinal sectional viewthrough the pump mechanismsubstantially asindicated by the line and arrows 1--1 of Fig. 6. i

Fig. 8 is a sectional viewthroughfthe pressure relief valvesubstantially as` indicated byfthe line andarrows S-BofFi i l i iself-contained unit that mounts on the standard propeller shaft, and infront of the engine nose. To the extent of being a self containedunit,the structure consists of a hub, a set of shiftable blades, pitchchanging mechanism or torque applying units for the blades, andautomatic control mechanism therefore built into a single assemblycomplete and ready for installation and operation upon an availablepropeller shaft or the like indicated at Ill. The engine nose, or gearcasing as it is sometimes called, usually ends in a cover plate I2outward from which the shaft I Il projects Vfor mounting of a desiredpropeller. The shaft iii provides a shoulder I 3 against which is seateda rear cone I4 and in front of which is a splined section I5 havingmating relation Witha complementarily splined hub I5 retained inposition by a front cone assembly I'I and a shaft nut I8.

In the illustrated embodiment the hub I5 has a rearwardly extendingsleeve portion 2G and radiating sockets 22 for reception of blades 24.The sleeve portion has a central aperture providing the splines 26 formating with the shaft splines I5 for transmitting torque from the drive`shaft to the hubfassem-bly. At the rear of the sleeve 20 a conicsurface bears upon the rear cone assembly I4 and with which it is forcedinto contact by the front cone assembly I1. Thus, the entire hub andblade assembly is securely mounted upon the propeller shaft I U by axialmovement of the hub assembly upon the shaft, thence engagement of thethreads in the nut I8 with the threads provided at the end of the shaftI0 and tightening of the nut I3.

The forward end of the sleeve 20 provides a Aplurality of radiallyextending bosses 30 each one of which is aligned and centered withrespect to a socket 22, each boss supporting an antifriction bearing 32the outer race of which is carried by or secured to a blade, as willpresently be described. Engaging the inner race of the antifrictionbearing is a cup-like spline member Se aligned with the boss 39 by meansof dowels 3B where it is held firmly in positioned by means of a tubularscrew 38 and a lock device lill. Secured within the screw 38 there is atube ft2 extending radially outward of the hub to be slidingly receivedby the central bore 44 of a piston member (it. Secured to the pistonmember there is a cylindrical skirt 48 whose inner lower surface issplined at 50 to mate with complementary splines 52 carried by themember 34, and whose outer surface is splined at 5ftV for matingrelation with the splines 56 provided on the inner cylindrical surfaceof a blade cylinder 58.

The two pairs of splines 5I), 52 and 54, 5S are characterized such thatfor any movement of the piston 4S along the tube 42 and within thecylinder '58, there will result a predetermined amount or rotationbetween the member 34 and the member 58. The hub spline 34 is maintainedin nonrotative relation with respect to the hub boss 30 by means of thescrew device 38 and the dowels 36, wherefore any longitudinal movementof the piston i6 relative to the hub spline 34 and the cylinder 58 willcause rotationr of the cylinder 58 with respect to the blade socket 22within which it is mounted. In the fabrication of the cylinder 5S it mayfor convenience be divided into two parts such as to include a tubularattaching portion 58a vprovided with a flange 60 engaging the outer raceof the antifriction bearing 32. An oilseal 62 may also be provided suchas to seal with the inside surface of the blade root The shank of theblade 24 is of a cylindrical contour and has an axial hollowed portion66 within which is mounted the blade shifting motors or torque applyingunits just described. In anchoring the blade within a socket a stack ofanti-friction bearings 68, here shown to be three in number, Vare passedover the blade root where they are retained by a blade nut 'IU threadedupon the root portion 64. A lock pin 'I2 may be threaded or otherwisedriven in to prevent rotation of the nut 'Ill from the end of the blade.

`In the hollow 66 of the blade a little beyond the cylinder 58 anassembly is provided for individually balancing each blade against amaster. For location of the .balancing means, a ring 'M is secured inplace within which is press fitted a cup 'I6 in inverted relation asshown in Fig. l, and where it `may be sweated in place. Centrally withinthe bottom of the cup 'I6 there is provided a stud 'I8 threaded toreceive a nut 80. A smaller cup 32 having outwardly flaring walls issecured inplace lconcentric with the bottom wall of the main cup, thusleaving Yan annular channel 84 for the anchorage of 'a predeterminedquantity of lead or balancing material .88. To perfect the fineness ofadjustment'in blade balance, a plurality of vshins 98 are provided tothread over the stud lwhere they are held in place by thenut 8D.

The torque applying units, consisting of the piston 46 and itscooperating cylinder 58 mounted as stated upon the hub lspline boss 3B`and supportinga blade moving gear 92 mounted upon the flanges 60 of thecylinder 58 by means of screws 94, are now ready for reception of andunion with the-blade assembly. The blade assembly carrying the stack ofbearings (it and the blade nut 7D along with a hub nut assembly 96 isthence passed into the open end of the socket 22, and the rootportionrll of the blade is lined ,up to receive the projecting end of adowel 98 nut 96 against the .bearing 32 to oppose centrifugal force ofthe revolving blade. Aseal Ill retained Within the nut assembly 95 bysnap ring IGZ closely surrounds the shank of the blade to prevent lossof lubricant. `A lock plate HM mates with aligned peripheral notches inthe socket 22 where it is held in place by a screw IBB threaded withlock Wire |08.

Fluid transmissionto and from the hub boss 3d, and thence to eithersideof the piston 46 is accomplished primarily as shown in Figs. 1, 4,5, and 10, where the tube secured in the nut 38 opens into a chamber IIUprovided by the boss 38 and from which exit is. made .to the exteriorofthe socket 22 by means of a .transfer tube II2. Thus the fluidconnection exits from the chamber IM between the cylinder 58 and pistons46, by way of the tube 42, chamber |||l to tube ||2. A similar tubeleads from the exterior of the socket 22 to a drilled passage ||6 forreception of a tubular dowel H3 that opens through the bottom of the hubspline member 34 into a chamber I Il between the lower end of the piston46 and the tubular screw 36. 'I'hus when iiuid under pressure isadmitted through one of the tubes ||2 or ||5 to one side of the piston46, then the fluid on the opposite side thereof is relieved through theother of the transfer tubes, and consequent movement of the piston 46within the cylinder 58 results in rotation of the blade shank 24 on itsbearings within the socket 22, thus effecting a shift in blade pitch.

In this embodiment the shift of the blade pitch is automatic and ishydraulically controlled so as to result in the speed of the propellerbeing substantially constant, or closely maintained with respect to apredetermined setting of a manual control device. A self-containedhydraulic regulator unit |29 is mounted `on the rearward sleeveextensionv 2i) of the hub and has iiuid connection with the transfertubes ||2 and H5 by means of tubular dowels I9 as shown in Figs. 4 and5.

The regulator comprises a plate member |22, a cover member |24 and asleeve |26 of an adapter assembly that are mounted in sealed relationsuch as to provide a regulator chamber |29 of annular form and withinwhich are mounted a pump mechanism |36, a relief valve |32, a governorvalve mechanism |34 and a breather valve assembly |36, each or" which ismounted on the plate member |22 or the cover |24 with appropriateconnections into the fluid circuit, and veach of which will be furtherdescribed in their turn. f

The regulator plate |22 is of annular form substantially as shown inFigs. 3 and 6, having an internal diameter |38 adapted to seat closelyabout the tubular extension 29 of the hub and closely adjacent theradiating sockets 22, substantially as shown in Fig. l. Embodied withthe plate there is a tubage assembly comprising a supply pipe |49, andtwo distributing pipes or central passages |42 and |44, all of the pipesbeing bonded to steel pads l4i, |48, |69, |52, |54, |56, |58 andmounting pad |69. The pipes -or passages |46, |42 and |44 desirablycomprise tube sections of preformed contour, held rigid- 1y inassociated relation by the steel pads 4that aid inv holding the tubageassembly in predetermined relation and form to act as inserts whilecastingthe plate |22. Certain oi the pads, to wit |46, |48, |52, |54 and|96, |36 are associated in pairs as respects the distributing pipes |42and |44. The pads |46, |62 and |56 each provide a passage |62 throughthe body of the plate and open into the distributing pipe |44, while thepads |46, |54 and |58 each provide a passage |64 opening into thedistributing pipe Thus when the plate |22 is assembled on the hubextension against the sockets 22, the distributing pipe |42 will throughits passages |64 align with the tubular dowels I9 communicate with thetransfer tube ||2, and the distributing pipe |44 will in a like mannercommunicate with the transfer tube l5.

The mounting pad |60 aside from aiording a rigid juncture oi the tubes|49, |42 and |44 acts as a support and juncture blocl; for mounting ofthe governor vlave mechanism |34 that selectively connects the pressuresupply pipe |49 with either of thepipes |42 or |44. The boss |66 of theplate |22 surrounding. the mounting pad |66 is drilled as at |68 forreception of mounting screws or studs |16 means of which the governorvalve mechanism is supported in operative relation.

An additional boss |42 of the plate located substantially diametric ofthe boss |66 is drilled out at |14 to provide a chamber for reception ofthe pump mechanism |39, and adrill way |16 opens from the chamber |24into the pressure tube |49. A similar drill way |18 opens from thechamber |24 through the wall of the boss to open into the regulatorchamber |28 thereby providing a pump intake. Thus the pump when set intooperation draws fluid in through the intake lili and discharges itthrough the outlet i6 into the pressure supply tube |49 through which itis delivered to the governed valve mechanism |34 and there distributedto either of the tubes |42 or |44 as the conditions call for.

The pump mechanism |39 comprises an assemblage of intermeshing pumpgears |89 enclosed with a pump casing |32 and adapted to be driven bygear |24 as will presently be explained. The pump mechanism is of theconventional constant delivery gear type as contrasted with one ofintermittent delivery and is mounted by means of a flange |96 throughwhich cap screws or the like |92 pass to thread into drill holes |99 ofthe boss |2. Bushings seated in the casing |92 closely t the pump gearsand prevent leakage. One of the gears |99 has its shaft eX- tended at|6| to provide a non-rounded or splined portion to afford drivingrelation by a hub |83 ofthe gear |34. To aiord proper bearing surfacethe hub |133 is journalled in the cover plate |35 of the casing, andwhich by means oi the spline connection |8| aiords somewhat of auniversal connection between the gear |84 and pump gear |36, all as isillustrated in detail in Figs. I, 6 and 7.

The regulator plate |22 at a point between the pump mechanism |39 andthe governor valve mechanism |34 provides a mounting boss |92 throughwhich the pressure supply pipe |40 passes. In that boss a passage |94 isprovided that connects into the passage .|49 and opens out at the faceof the boss |92. The relief valve |32 is mounted by means of screwdevices |96 threaded into the boss |92. The relief valve mechanism isshown in detail in Fig. 8 and comprises a block |99 providing a valveport 299 with a passage 262 communicatingY with the passage |94,

and a plunger recess 2 94 having a side port 294A opening directly intothe regulator chamber |28; In the recess 294 a valve plunger 268 isassembled and urged by means of a spring 2||i linto closing relationwith the valve port 296, the spring acting against a cap 2|2 secured tothe body |99. The plunger valve is so characterized and positioned as tobe normally closed against the port 209 by the spring 2|@ while themechanism is at rest, and such that centrifugalforce acting upon thevalve member when the assembly is in rotation will tend to urge thevalve against its seat. However, upon the development of a predeterminedpressure within the pressure supply pipe |46 the valve will be raisedfrom its seat which will allow the excess of pressure to be relievedinto the regulator chamber through the port 266. Thus, the system isVprotected'against excessive or dangerous pressure.

All of the tubes |49, |42 and'l44 have their remote extremities sealedoi'as indicated at 2|4 Ymunicates with the pressure supply line `fromthe axis of propeller rotation o o.

respectively are secured in the mounting pad I Ell, the latter providingports 222, 224 andf226 respectively opening from the face of themounting pad and communicating respectively with the pipes of the tubageassembly. Thus the port 222 colrrai- :da through 2|5, while the ports224, 226 identify the distributing lines |42, and |42 respectively.

For selectively connecting the pressure supply line |40 with either ofthe distributing or control passages the governor valve mechanism |32mountslon or over the pad I Boland automatically responds to propellerspeed, or a function there- Yof, inaccordance with a manual adjustmentand setting. The governor valve assembly |32, like the pump assembly |30and the relief valve |32,

is complete in itself as a unit, and is mountable upon and removablefrom the supporting station of the ,regulator plate |20 by means of thescrew devices I'IE! threading into the tapped drillways |68.Specifically, the governor valve assembly comprises a valveblock 23Dhaving a longitudinal bore232 for reception of a porting sleeve 23d. Thesleeve 234 has a flange 236 abutting the block 23D at one end of thebore and is secured in place by a cross pin 238 at the opposite end ofthe block 238. The sleeve 234 is ported at 24D, 222 and 242 in vregistrywith cross bores or recesses 248, 248 and 250 extending from themounting face of the valve block 23|) across the longitudinal bore 222.The cross bores or recesses 248, 258 and 25!) are so positioned as toline up with the ports 222, 222

Vand 226 respectively in the mounting pad |62.

Within the porting sleeve 232 there is a valve member 252 having lands254 and 256 so spaced as to coincidentally cover the ports 222 and 242,`the valve member being movable along the porting sleeve 232 so as toselectively connect the port 242 with either of the ports 240 or 244.

The radially inward end of the valve member 252 has a pivotal connection251 with a lever 258, the outer end ofwhich rests upon a movablefulcrurn roller 260. At an intermediate point the lever 25B carries aspring seat 252 for one end of a spring k26H engaging an adjusting nut268 threaded upon a threaded stud 268. The nut 286 provides a lateralextension 210 adapted to ride in a slot 212 provided by the near side ofthe valve block 23B. An overhanging portion 212 from the valve block isapertured to receive the member `258 which has a flange 218 for lockingengagement with the extension. For supporting the fulvcruin roller .268there isa slider assembly 228 supporting the roller and riding on a pairof `.arms 280 secured to the inward end of the valve block 230.Theslider block2I8 has a depending or inwardly extending portion 232that provides a shoe 284 adapted to travel in a circumferential groove285 of a control ring 288.

"With reference to ',Figs. 1 and 10, it will be observed that thegovernor or distributing valve 252 is arranged lengthwise with respectto a radius It therefore responds to centrifugal force and facts againstthe opposing force of the spring 282 through the arm 258 having arelatively fixed point of bearing on the fulcrum roller 28D. Adjustmentof the spring 264 and movement of the fulcrum roller 268 along the guidearms 288 will operate to determine thepoint at which the valve lmember252 will establish a constant speed, or in other words, will determinethe speed of rotation at which the valve within the ported sleeve 234will equalize or balance fluid pressures in the distributing lines `|42and |44. `If theregis an increase of speed over that for which thebalance condition obtains then the valve member 252 will move radiallyoutward and connect the fluid pressure line |49 with the distributingpipe |44 whereby pressure is admitted to that side of the piston diithat will effect an increase in blade pitch and result in establishingso much additional load on the blades as to cause a consequent drop inspeed of rotation of the propeller, which immediately brings theapparatus back to the specified setting. On the other hand, if the speedof rotation falls below the predetermined setting the spring 284 willoperate to overbalance the centrifugal force on the valve member 252which allows the valve to move radially inward toward the axis ofrotation. In so doing the valve 252 operates to connect, the pressureline |60 with the distributing line |42 and thence by the associatedtransfer tubes to the opposite side of the piston 46 which tends todecrease the pitch of the blade and allow the speed of rotation toincrease.

The adjustment that is to be effected through the screw device 228 isone that is designed to be made upon the ground, or while the propelleris at rest, and is for the purpose of adjusting the governor mechanismwith respect to the general requirements of the engine with which it isassociated. Once it is established, it is for the most part allowed toremain in ythat fixed condition. In the operation of an air-craft,differing relation of propeller pitch are desirable during the cycles ofengine warm-up, take-off, climb, cruising, and dive or other maneuvers.To effect manual control so as to accomplish immediate setting of theregulator mechanism best suited for the desired conditions, means areprovided for shifting the fulcrum roller 26D along the guides 222 so asto modify the moments of centrifugal and spring force acting upon thelever 258 and to rearrange their relations or proportions.

Shifting of the fulcrum roller is accomplished by movement of thecontrol ring 288 along or in the direction of the length of the sleeve2U. The

ring 288 is slidably mounted on the sleeve |26, and the relativeposition thereof is accomplished by a plurality of screw shafts 228having a steep pitched threadpassing through the ring, and a plainportion 292 journalled in the rearward thickened portion of the sleeve|26. A stop collar 282 acts as a thrust member on lthe shaft 292 whichalso passes through a, ring 295 assembled aga-inst an adapter ring 298.The adapter ring 298 is channeled to receive a ring gear 388 that mesheswith pinions 382 on the end of the screw shafts 222. An arm 354 joinsthe ring gear 30|) and has provisions for rod or cable connectionsleading to the pilots compartment. Rotation of the ring gear 328 causesall of the screw shafts 298 to rotate in unison and as they do so theythread into or out of the ring 288 causing the latter to move axially ofthe sleeve I 26. The shoe 28d riding in the groove 283 of the ring 288transmits that reciprocable motion to the slider which carries thefulcrum roller 258 toward or away from the point of spring pressure uponthe lever 258.

The sleeve |28 with the ring 288, screw shafts and rings 296, 293 and308 may for convenience be known as an adapter assembly, and may besecured together as shown in Figs. 8 and 9 by means of screws or likedevices 3BE. The adapter assembly constitutes a fixed assembly securedto the cover plate I2, as shown in Fig. l, through the agency of thestuds and nuts 388. When so mounted the sleeve |23 extends into theregulator chamber |23 providing an inner circular wall for the chamber.A toothed flange 3|3 on the sleeve |26 engages the pump driving gear |33such that upon rotation of the propeller the pump driving gear |84willroll about the toothed flange 3 il.

The opposite ends of the sleeve member |23 provide cylindrical seats onwhich are secured oil seals 3i2 and 3M. The cover member |23 is rabbetedat 3|@ to receive a gasket 3i3 and to mate up with the peripheral edgeof the plate |22 where it is secured by a plurality of screws or thelike 323. At a point in the peripheral wall of the cover |24 opposite tothe adjusting stud 268 there is provided a threaded aperture to receivea screw plug 322 which facilitates charging the chamber |23 with theproper amount of fluid, and for adjustment of the spring 232. The endwall of the cover member has formed therein an undercut or channel 323which may be used as a slinger ring into which is discharged antiicingfluid which may be conducted to the roots of the blade.

The regulator assembly being completed, that is, with the controlelements mounted upon the plate |22 and enclosed by the cover |23 andsleeve |26, it is thence in preparation for mounting on the propellerhub which is accomplished by slipping the regulator assembly over therearward extension 2li of the hub and thence threading into place theregulator nut 323. That being done the mechanism contained within thechainbcr |23 is properly oriented and hydraulically connected throughthe agency of tubular dowels H3 and -the respective transfer tubes withthe blade shifting motors or torque applying units. The hub assemblythus constructed is ready for mounting upon the propeller shaft i3 whereit seats against the inner cone M with the adapter ring 293 securedagainst rotation by the case screws and nuts 333. Application of theforward cone 33, by tightening the shaft nut i8 will secure the hub inoperative relation upon the shaft ill.

For maintaining the tightness of the nut i3 and also to make it moreaccessible in tightening the installation there is provided a sleeveassem bly having lug and notch engagement with the end of the nut i8 andextending forward thereof beyond the terminal rim 332 of the hub i6 andending in wrench notches 333. Intermediate its ends the sleeve assemblyprovides a flange 335 appropriately notched to receive tongues 333 onthe end of a spinner adapter 3133. rThe sleeve assembly 33s also carriesl shaped leaf springs 332 having an upturned free end adapted to engagethe end of the tongues 333 when they are passedthrough the notches ofthe iiange 336. Closely fitting about the fiange 333 of the sleeveassembly there a anged sleeve 33d that is secured to the terminal `rirn332 by means of a plurality of screw devices 3553.' The member 3M hasrearward tubular extension i333 telescoping within the bore 353 of thehub i8 so as to end beneath the hub spline bosses 33, lhis sleeveextension forms a bearing for a coor dinating gear 352 meshing with alloi' the blade shifting gears 32.` coordinating gear has a' sleeveportion 35d machined to form the inner race of friction reducing bearing335 whose outer race 332i is maintained in position by spring ring 335i.rThe member 3M when brought into position by the screws 33t acts as athrust member for the friction reducing bearing 333. Thus byappropriately mating up the sleeve assembly 333 with the nut ls, and thenotches end of the spinner adapter 34e with the notched flange 336, theapertures in the flange of the spinner adapter Amay be properly alignedwith the threaded apertures in the member 334 for reception of thescrews 3M. Thus a positive lock is provided for maintaining the nut itin tightened relation upon the end of the shaft lil.

yThe forward free end of the spinner adapter 333 is chamfered off at 312to blend in with the rounded contour of a nose ring 3M. The nose ring3l@ forms a forward reinforcing extremity for a thin metal shell member316 generally conic in form and which has a forward flange 3`i3 seatingin a recess 380 of the nose ring where it is firmly secured by screwdevices 382. The union of the nose ring to the spinner adapter 333 isslidable, such that the spinner adapter forms a pilot for positioningthe forward end of the spinner. The spinner shell 316 increases indiameter rearwardly toward the fuselage or the hose piece of the engineand ends aft of the blades 2li. To rigidify the spinner shell 3`i3,intermediate its length a ring 384 of angular cross section is securedto the spinner shell by rivets 336 or the like. At appropriate pointsthroughout its circumference the shell 316 is notched at 338 to pass theshanks of the blades 2li, while the intervening webs are secured at theterminal ends by rivets 333 to flanged arcsl 392.

The base end of rear of the shell Slt is supported by means of a platemember 332 secured at its inner periphery beneath the screws 32|), or atleast a part of them, holding the regulator plate |22 and cover |24 inassembly. rlhe'plate 336| is provided with a series of apertures 396located in a circular row between the inner and outer periphery. Theouter periphery of the plate 334 is bent into a flange 398 thatrigidifies the construction and provides a relatively fiat surface forseating the flanged arcs 332. in a circular row between the flange 333and the row of apertures 336 there are mounted a plurality of pilotstuds 43) adapted to be received in apertures of the inner flange of theflanged arcs 392.

At spaced points on the flange 393 removable inserts 432 are secured byscrew devices 339,*the forward ends of the inserts having a circularnotch 533 to close about the rear circumference of the blade shank 2li.These inserts are of greater width than is the width of the notch 383 inthe member 313, and the opposite straight edges are offset at 436 so asto be received inside of and overlapping the member 376 along the extentof the notches, thus completing the spinner surface at the rear of theblades. l

.With the supporting plate 334 mounted in place, the spinner assembly ispassed over the hub so as to straddle the blades and slide over thespinner adapter 333v with the base end of the shell Slt passing over theflange 333 of the plate, it being piloted by the elements 433 whichscrew devices secure the assembly in place.

When the assembly and installation is cornplete the filler plug 322 isremoved and a definite quantity of hydraulic fluid is placed within thechamber t28, and with the replacement of the plug 322 the installationis ready for service. The charge of fluid used is of a quantity thatwould ordinarily leak out of the chamber or reservoir |23 while theapparatus is at rest, were it not for the seals 3|2 and 3M. While thepropeller is in a state of rotation the hydraulic fluid is always thrownoutwardly from the axis of rotation o-o against the peripheral wall ofthe cover member |24, such that during a state of rotation there is nocondition of leakage past ll the oil seals 312 and 314 While thepropeller is rotating at ground level the pressures within the reservoir|28 and outside thereof are substantially equal and near to atmosphericpressure. With the propeller rotating while climbing to a higheraltitude, there would develop a difference of pressure within andwithout the reservoir. The pressure within the reservoir would remainsubstantially the same as at ground level while that without at a higherelevation matey rially decreases, in consequence of which the hydraulicfluid within the reservoir might be forced outwardly past the oil sealsSI2 and 314. To overcome these difiiculties the structure illustrated inFig. 9 is made use of.

The oil seals 312, 314 may be identified as housing seal and cover sealrespectively. Inasmuch as each is essentially the same in physicalcharacter the description of one will sunice. Each of the sealscomprises a ring of Soft iiexible rubber or the like 410 of channelshape in cross section, and whose inner periphery is bonded to a flangedrigid ring 412 adapted to be press fitted or otherwise secured in aperipheral notch 414 or 416 on either end of the sleeve 12B. The insidesurface of the outer flange of the rubber ring is notched at 418 toreceive a Coil of the garter type spring 421), and which is normallyunder compression such as to urge the outer flange of the rubber ringradially outward. The regulator plate 122 provides a ledge in which issecured a bearing ring 422 of angular section having one leg thereofconstantly in rubbing contact with the outwardly stretched flange of therubber ring 414.

During a condition of rest the outer flange of the oil seal is forcedradially outward with sufiicient force by the spring 42B to preventmaterial leakage of hydraulic fluid at the bearing surface between therubber ring and the bearing ring 422, and likewise the bearing ring 424carried by the coverplate 124. Provisions are made for returning to thereservoir 126 any hydraulic fluid that may nd its way past either of theseals. With respect to the cover seal, the bearing ring 424 ischaracterized by a shallow peripherial groove 426 in the cylindricalwall near the bend of the angle, and situated such as to be exterior ofthe corresponding rubber ring. An oblique radially extending drillpassage 428 leads from the bottom of this channel 425 and opens into apassage 434 communicating with the reservoir 128 on the interior side ofthe cover 124. That construction makes possible for draining anyhydraulic fluid escaping between the bearing ring and cover oil sealback into the reservoir or chamber 12S, and also provides a breatherbetween the interior and exterior of the regulator.

For controlling the passage of air or hydraulic fluid through thepassages 428, 434 a centrifugally operated valve is provided thatoperates to close the passage while the apparatus is at rest thuspreventing leakage or loss of the hydraulic uid, and that also operatesto open under certain conditions of operation such that pressures withinand without the regulator may become substantially equalized.

The last mentioned structure is embodied in the breather valve referredto as it and comprises a block 432 adapted to be mounted upon the innersurface of the cover 124 by means of screw devices 434. The block has apassage 43B mating up with the passage 430, and from the passage 435there leads a port 438 into a cylindrical housing 444. The housingportion 443 extends radially outward and encloses a valve rod 442carrying a valve 444 urged by a spring 446 to close off the port 438.The outward end of the housing 444 is closed by a plug 448 that alsoacts to guide the rear end of the valve rod 442. Under centrifugal forcethe valve rod 442 and valve head 444 are moved away from covering theport 438 and opens communication between the bore 433 and the chamber128 through one or more side ports 454. Thus under a condition ofrotation any hydraulic fluid that may have worked its way to the spacebetween the rubber ring 412 and bearing ring 424 collects in the channel426 and by centrifugal force passes through the drill holes 428 andthence through 431i, 436, 438 and 454 thereby returning to the reservoiror chamber |28. The oil drain and breather valve structure firstdescribed may be duplicated for the bearing seal 312. Through the samepassages that are so provided any difference of pressure that wouldnormally exist between the interior and exterior of the regulatorhousing is equalized. That is, the higher pressure within the housingmay be reduced to near that of the surrounding atmosphere without theconsequence of uid leakage. Under a condition of rest the valve head 444is spring urged to close the port 438 which thus stops leakage of thehydraulic fluid in a reverse path through the sealed drain passages.Further, the pressures within and without the reservoir will besubstantially equal at all times because of the open conditions of theseal drain passages during the whole period that the craft will bechanging altitude or so long as the propeller is rotating.

While the embodiment of the present invention is herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

l. In a hydraulically controlled constant speed propeller, having a hub,the combination comprising, a regulator mechanism mounted for rotationwith the hub and providing a fluid containing reservoir surrounding thehub, nonrotating means extending into the reservoir and providingoilseals engaged by the rotating part or" the reservoir, a channel onsaid reservoir disposed adjacent an exterior surface on one of theoilseals for collecting any fluid that seeps past said one oilseal, anda breather valve within the reservoir and mounted thereon providing avalved passage for bypassing one of the oilseals, said passageconnecting the bottom of said channel with the interior of saidreservoir said breather valve having a weight element and being normallyclosed under the urge of spring pressure but adapted to open in responseto a predetermined speed of rotation for Venting the interior of thereservoir to outside atmosphere and to permit return 'to the reservoirof any fluid that has seeped past the oilseals.

2. 1n a propeller having a reservoir rotatable about a fixed sleeve andproviding cooperating parts containing a quantity of fluid medium, thecombination of means sealing the rotatable joint against loss of fluidmedium and equalizing pressures within and without the reservoir, saidmeans comprising yieldable seal rings between the rotating reservoir andxed sleeve and having rotatable engagement with one of the cooperatingparts, said one cooperating part providing a channel on the atmosphericside of the seal ring, a by-pass duct provided by said one cooperatingpart leading from the bottom of 13 said channel back to the interior ofthe reservoir, and a centrifugally responsive valve for controllingiiuid passage through said by-pass duct.

3. The combination set forth in claim 2 wherein the valve comprises achambered block carried by said one cooperating part and providing ahousing extending radially of the axis of reservoir rotation, meansproviding ports at the radially inward end of said housing one of whichports is in communication with the by-pass duct, a spring pressed valveplunger within said housing normally closing` said one port and adaptedunder the urge of centrifugal force to uncover said one port.

4. In a propeller having a reservoir rotatable about a fixed sleeve andproviding cooperating parts containing a quantity of fluid medium,resilient seal rings carried by the fixed sleeve and rotativelyengageable with the reservoir, means on the reservoir providing anannular channel on the atmospheric side of the resilient seal, means onthe reservoir providing a return passage extending from the bottom ofsaid channel around the seal connection to open into the reservoirinterior, a spring pressed valve assembs s ly mounted within thereservoir normally closing said return passage and having a Weightelement responsive to centrifugal force incident to reservoir rotationfor opening the passage to fluid ow through said return passage, wherebypressure within and without the reservoir will be equalized duringreservoir rotation, and whereby loss of fluid from the reservoir whileat rest will be prevented, any liquid medium `reaching the channel onthe atmospheric side of the seal being drained back to the reservoirduring reservoir rotation. i

5. In a hydraulically controlled constant speed propeller, a regulatormechanism for rotation with the propeller and providing a iiuidcontaining reservoir, nonrotating means extending into the reservoir andproviding oil seals engaged by the rotating part of the reservoir,constant delivery pressure developing means carried by the reservoir andhaving driving engagement with said nonrotative part, pressuredistributing means Within the reservoir supplied with fluid underpressure by said pressure developing.

means having an intake from said reservoir, a channel on said reservoirdisposed adjacent an exterior surface of one of the oil seals forcollecting any iiuid that escapes past said one oil seal, and a breathervalve assembly connected around one of said oil seals for returning uidescaped past the seals to the reservoir and for equalizing thedifferential of pressure within and without the reservoir incident tothe pressure developing means taking up fluid from said reservoir, saidbreather valve assembly comprising means pro- Viding a fluid passageextending from the inside of said reservoir to the bottom of saidchannel, a spring urged valve located within said uid passage andincluding a weight element for unseating the valve at a predeterminedrotative speed of the reservoir.

6. A propeller controlled mechanism `for an hydraulically adjustablespeed propeller of the character described which comprises a housingrotatable with the propeller shaft, a reservoir provided by said housingfor receiving a quantity of pressure actuated fluid, a relatively xedsleeve about which the reservoir is rotatable, means normally sealingthe reservoir with respect to the fixed sleeve against iiuid leakage,means providing a normally closed passage forming a bypass around saidsealing means, a channel on the reservoir disposed adjacent an exteriorsurface of said sealing means, said passage connecting the bottom ofsaid channel with the interior of said reservoir, and centrifugallycontrolled means operable while the mechanism is under a state ofrotation to open said passage for returning fluid passing by the sealingmeans, to the reservoir.

7. A combination set forth in claim 6 wherein the relatively ilxedsleeve extends from a nonrotating part into the reservoir, and iiexibleseals carried by the xed sleeve are engageable with the said rotatingpart, means locating the seals at the juncture of the housing and sleeveso as to be out of contact with the pressure actuated fluid when themechanism is rotating, and means providing the passage with a springpressed valve. said passage and valve being carried by said rotatingpart for connecting the reservoir with the outside air around the sealat a predetermined speed of rotation.

WERNER J. BLANCHARD. JOHN F. HAINES. THOMAS B. MARTIN. ELISE M. MACNEIL,Administratri of the Estate M ac Neil, Deceased.

REFERENCES CITED The following references are of record in the file ofthis patent:

` UNITED STATES PATENTS Number Name Date 2,113,438 Allred Apr. 5, 19382,147,078 Barish Feb. 14, 1939` 2,307,101 Blanchard et al Jan. 5, 19432,307,102 Blanchard et al. Jan. .5. 1943 2,352,336 Martin et al. June27, 1944 2,357,400 Haines Sept. 5, 1944 FOREIGN PATENTS Number CountryDate 480,082 Germany Mar. 14, 1939 of Charles S. J.

